1. Field of the Invention
The present invention generally relates to tape cassettes and, more particularly, to a tape cassette having front lid and a back lid for covering the tape inside the cassette when it is not in use and which are opened during use to allow the tape to be withdrawn to the outside of a cassette casing so that one portion of the tape extends along a tape withdrawing area between tape exit portions formed at two ends of a front wall of the cassette casing.
2. Description of the Prior Art
In one type of tape cassette utilizing a record medium tape, for example, a magnetic tape, a front lid is rotatably attached to the cassette casing so that the front lid is movable between a lid closed position for covering the front wall of the cassette casing, and a lid opened position for exposing the front wall. The front lid functions to protect the tape, which extends along the front wall of the cassette casing, from dust and from being touched by fingers and the like. The front lid is commonly comprised of a main portion which covers the front wall of the cassette casing. Supported portions protrude from left and right ends of the main portion, wherein the supported portions are rotatably supported by the left and right side wall portions of the cassette casing.
A conventional tape cassette is provided with a tape withdrawing recess portion opened in the front and lower directions in order to place a tape withdrawing member behind the tape when the tape cassette is loaded on the recording and/or reproducing apparatus. The tape withdrawing recess portion is formed between two tape exit portions provided at left and right end portions of the front wall of the cassette casing. Further, in order to protect the tape from being touched with fingers or the like entered through the tape withdrawing recess portion, a conventional tape cassette is provided with a back lid which covers the tape from the rear side independently from the front lid.
Because the front lid functions to protect the tape when the tape cassette is not in use, the front lid must be locked in the lid closed position. To this end, this type of tape cassette is generally provided with a locking device which locks the front lid in the lid closed position. In the prior-art tape cassette, one side end portion of the front lid, for example, one of the left and right supported portions is locked by the locking device. Japanese Utility Model Published Gazette No. 63-1606 describes a tape cassette having such a locking device.
However, with respect to the configuration of the tape cassette, the dimension in the left to right direction is large compared to the thickness, as seen from the front wall side. Accordingly, the main portion of the front lid is generally shaped in a narrow rectangular configuration that is long in the left to right direction. Therefore, the mechanical strength of the front lid against deformation is decreased. As a result, if the other side end portion of the front lid is pushed in the lid opening direction, without releasing the front lid from its locked state, the other side end portion of the front lid is displaced while the front lid is twisted, exposing one portion of the tape to the outside. Further, there is the substantial disadvantage that the front lid will be deformed or the front lid will be damaged.
In order to remove the above-mentioned shortcomings and disadvantages, it is proposed that the thickness of the front lid be increased or that the front lid be locked at its left and right side portions. According to this proposal, the weight of the tape cassette is increased or the number of locking devices is increased, which unavoidably increases the number of assembly parts of the tape cassette. Further, another problem is that the number of lock releasing devices provided in the recording and/or reproducing apparatus must be increased in order to release the locking devices.